Many portable electronic devices include displays for displaying various types of images. Examples of such displays include electrowetting displays (EWDs), liquid crystal displays (LCDs), electrophoretic displays (EPDs), light emitting diode displays (LED displays), etc. In EWD applications, a plurality of pixels is defined between first and second substrates or support plates that are coupled together. The plurality of pixels is generally defined by pixel walls on the first substrate. In various EWD applications, spacers on the second substrate engage the pixel walls. The spacers provide mechanical support that protect the EWD from damage due to physical impact. The spacers also maintain a parallel distance between the two substrates, i.e. the spacers help maintain a consistent pixel cell height.
Furthermore, the second substrate in the EWD generally comprises glass and the spacers help prevent the glass substrate from bending and touching the first substrate. If the glass substrate bends and contacts the first substrate, electrowetting oil in the pixel may stick to the glass substrate. Such an “oil pick-up” is a non-reversible fault that causes black spots and empty pixels within the EWD. Additionally, since the height of the spacers and the height of the pixel walls can vary due to manufacturing tolerances, gaps between the spacers and the pixel walls can occur. Applying pressure to the glass substrate and moving the pressure can cause a “whitening” effect in the EWD. This whitening effect is generally a streaking white appearance on the EWD. Fluid that includes an electrolyte and the electrowetting oil are generally moved among the pixel cells thereby creating the whitening effect. The oil pick-up and the whitening effect are generally attributable to movement of the spacers and the pixel walls relative to each other.